1. Field of the Invention
The present invention relates to a image data transmission system, a video server unit, and a client unit used for a video on demand (VOD) system in which image data (video) are transmitted through a network.
2. Description of the Related Art
Recent years have seen significant advances in the area of high speed networks and information compression techniques, and image data transmission is becoming increasingly popular. In this situation, the VOD system, which enables users to watch favorite videos and films in any location, including homes and offices at any desired time, is expected to be popularized as one of the more important applications in the age of multimedia applications.
In a conventional VOD system, the ATM (Asynchronous Transfer Mode) is applied to the transmission of image data and the UDP (User Datagram Protocol) is used as a protocol for the transmission of image data.
However, the problem of data loss of the image data transmission before a client unit displays the image, does not take into account the image data transmission according to the ATM and the UDP protocol. If the loss of image data in the transmission is caused because of, for example, insufficient capability of the client unit, the image to be displayed becomes disordered and awkward, which is an undesirable problem.